Your local hydro shop should have a feeding guide for Foxfarm products and it breaks down exactly what to do week by week for soil and hydro.
Basically for soil you will be using Grow Big for pretty much the whole grow. At different stages you add other nutrients that are specific to that stage in with the Grow Big.
For example, during vegetative growth you will be using Grow Big along with their liquid plant food Big Bloom. Towards the end of the vegetative stage you will add tiger bloom and Open Sesame to the mix as well for a few weeks with every other watering then eventually end up switching your light cycle to 12/12.
Once the Open Sesame is done being used and flowering has begun your water mix will contain grow big, big bloom, tiger bloom and for a few more weeks with every other watering beastie bloomz. Eventually you will switch out beastie bloomz for cha-ching about a month before harvest.
Foxfarm makes some great products that produce excellent results but like with any fertilizer use less and work up to full strength over a week or two so that you dont stress or burn your babies.
Also if you are going to use their nutrients you should also use their soil. I personally mix ocean forest with light warrior 60-40% to end up with what I think is a perfect growth medium.
Ph with or without nutrients should be very close to 6.5. When you need to use ph up or down just follow the directions on the packaging and then I give it a gentle shake to make sure it runs its process on all of the water evenly.